NTFS-3G(8)NTFS-3G(8)NAME
ntfs-3g - Third Generation Read/Write NTFS Driver
SYNOPSIS
ntfs-3g volume mount_point [-o option[,...]]
mount -t ntfs-3g volume mount_point [-o option[,...]]
DESCRIPTION
ntfs-3g is an NTFS driver, which can create, remove, rename, move
files, directories, hard links, and streams; it can read and write
files, including streams and sparse files; it can handle special files
like symbolic links, devices, and FIFOs; moreover it can also read and
create transparently compressed files.
The volume to be mounted can be either a block device or an image file.
Access Handling and Security
By default, files and directories are owned by the effective user and
group of the mounting process and everybody has full read, write, exe‐
cution and directory browsing permissions. You can also assign permis‐
sions to a single user by using the uid and/or the gid options together
with the umask, or fmask and dmask options.
Doing so, Windows users have full access to the files created by
ntfs-3g.
But, by defining a Windows-to-Linux user mapping in the file
.NTFS-3G/UserMapping, you can benefit from the full ownership and per‐
missions features as defined by Posix and those ownership and permis‐
sions will be applied to Windows users and conversely.
If ntfs-3g is set setuid-root then non-root users will be also able to
mount volumes.
Windows Filename Compatibility
NTFS supports several filename namespaces: DOS, Win32 and POSIX. While
the ntfs-3g driver handles all of them, it always creates new files in
the POSIX namespace for maximum portability and interoperability rea‐
sons. This means that filenames are case sensitive and all characters
are allowed except '/' and '\0'. This is perfectly legal on Windows,
though some application may get confused. If you find so then please
report it to the developer of the relevant Windows software.
Alternate Data Streams (ADS)
NTFS stores all data in streams. Every file has exactly one unnamed
data stream and can have many named data streams. The size of a file
is the size of its unnamed data stream. By default, ntfs-3g will only
read the unnamed data stream.
By using the options "streams_interface=windows", you will be able to
read any named data streams, simply by specifying the stream's name
after a colon. For example:
cat some.mp3:artist
Named data streams act like normal files, so you can read from them,
write to them and even delete them (using rm). You can list all the
named data streams a file has by getting the "ntfs.streams.list"
extended attribute.
OPTIONS
Below is a summary of the options that ntfs-3g accepts.
uid=value and gid=value
Set the owner and the group of files and directories. The values
are numerical. The defaults are the uid and gid of the current
process.
umask=value
Set the bitmask of the file and directory permissions that are
not present. The value is given in octal. The default value is 0
which means full access to everybody.
fmask=value
Set the bitmask of the file permissions that are not present.
The value is given in octal. The default value is 0 which means
full access to everybody.
dmask=value
Set the bitmask of the directory permissions that are not
present. The value is given in octal. The default value is 0
which means full access to everybody.
usermapping=file-name
Use file file-name as the user mapping file instead of the
default .NTFS-3G/UserMapping. If file-name defines a full path,
the file must be located on a partition previously mounted. If
it defines a relative path, it is interpreted relative to the
root of NTFS partition being mounted.
When a user mapping file is defined, the options uid=, gid=,
umask=, fmask=, dmask= and dsilent= are ignored.
default_permissions
Use standard access control. This option requires either a user
mapping file to be present, or the options uid= and gid= of a
user to be defined. This option is set by default when a user
mapping file or an ownership related option is present.
inherit
When creating a new file, set its initial ownership and protec‐
tions according to inheritance rules defined in parent direc‐
tory. These rules deviate from Posix specifications, but yield a
better Windows compatibility. A valid user mapping file is
required for this option to be effective.
ro Mount filesystem read-only. Useful if Windows is hibernated or
the NTFS journal file is unclean.
locale=value
This option can be useful when wanting a language specific
locale environment. It is however discouraged as it leads to
files with untranslatable chars to not be visible. Please see
more information about this topic at http://ntfs-3g.org/sup‐
port.html#locale
force Force the mounting even if the NTFS logfile is unclean. The log‐
file will be unconditionally cleared. Use this option with cau‐
tion and for your own responsibility.
remove_hiberfile
Unlike in case of read-only mount, the read-write mount is
denied if the NTFS volume is hibernated. One needs either to
resume Windows and shutdown it properly, or use this option
which will remove the Windows hibernation file. Please note,
this means that the saved Windows session will be completely
lost. Use this option for your own responsibility.
atime, noatime, relatime
The atime option updates inode access time for each access.
The noatime option disables inode access time updates which can
speed up file operations and prevent sleeping (notebook) disks
spinning up too often thus saving energy and disk lifetime.
The relatime option is very similar to noatime. It updates
inode access times relative to modify or change time. The
access time is only updated if the previous access time was ear‐
lier than the current modify or change time. Unlike noatime this
option doesn't break applications that need to know if a file
has been read since the last time it was modified. This is the
default behaviour.
show_sys_files
Show the system files in directory listings. Otherwise the
default behaviour is to hide the system files. Please note that
even when this option is specified, "$MFT" may not be visible
due to a glibc bug. Furthermore, irrespectively of
show_sys_files, all files are accessible by name, for example
you can always do "ls -l '$UpCase'".
allow_other
This option overrides the security measure restricting file
access to the user mounting the filesystem. This option is only
allowed to root, but this restriction can be overridden by the
'user_allow_other' option in the /etc/fuse.conf file.
max_read=value
With this option the maximum size of read operations can be set.
The default is infinite. Note that the size of read requests is
limited anyway to 32 pages (which is 128kbyte on i386).
silent Do nothing on chmod and chown operations, but do not return
error when the user mapping file required by these operations is
not defined. This option is on by default.
no_def_opts
By default ntfs-3g acts as "silent" was passed to it, this
option cancel this behaviour.
streams_interface=value
This option controls how the user can access Alternate Data
Streams (ADS) or in other words, named data streams. It can be
set to, one of none, windows or xattr. If the option is set to
none, the user will have no access to the named data streams.
If it's set to windows, then the user can access them just like
in Windows (eg. cat file:stream). If it's set to xattr, then the
named data streams are mapped to xattrs and user can manipulate
them using {get,set}fattr utilities. The default is xattr.
user_xattr
Same as streams_interface=xattr.
efs_raw
This option should only be used in backup or restore situation.
It changes the apparent size of files and the behavior of read
and write operation so that encrypted files can be saved and
restored without being decrypted. The user.ntfs.efsinfo extended
attribute has also to be saved and restored for the file to be
decrypted.
debug Makes ntfs-3g to not detach from terminal and print a lot of
debug output from libntfs-3g and FUSE.
no_detach
Same as above but with less debug output.
USER MAPPING
NTFS uses specific ids to record the ownership of files instead of the
uid and gid used by Linux. As a consequence a mapping between the ids
has to be defined for ownerships to be recorded into NTFS and recog‐
nized.
By default this mapping is fetched from the file .NTFS-3G/UserMapping
located in the NTFS partition. The option usermapping= may be used to
define another location.
Each line in the user mapping file defines a mapping. It is organized
in three fields separated by colons. The first field identifies a uid,
the second field identifies a gid and the third one identifies the cor‐
responding NTFS id, known as a SID. The uid and the gid are optional
and defining both of them for the same SID is not recommended.
If no interoperation with Windows is needed, a single default mapping
with no uid and gid can be used. Just copy the example below and
replace the 9 and 10-digit numbers by any number not greater than
4294967295.
::S-1-5-21-3141592653-589793238-462643383-10000
If interoperation with Windows is needed, the mapping has to be defined
for each user and group known in both system, and the SIDs used by Win‐
dows has to be collected. This will lead to a user mapping file like :
john::S-1-5-21-3141592653-589793238-462643383-1008
mary::S-1-5-21-3141592653-589793238-462643383-1009
:smith:S-1-5-21-3141592653-589793238-462643383-513
::S-1-5-21-3141592653-589793238-462643383-10000
The utility ntfs-3g.usermap may be used to create the user mapping
file.
EXAMPLES
Mount /dev/sda1 to /mnt/windows:
ntfs-3g /dev/sda1 /mnt/windows
or
mount -t ntfs-3g /dev/sda1 /mnt/windows
Read-only mount /dev/sda5 to /home/user/mnt and make user with uid 1000
to be the owner of all files:
ntfs-3g /dev/sda5 /home/user/mnt -o ro,uid=1000
/etc/fstab entry for the above:
/dev/sda5 /home/user/mnt ntfs-3g ro,uid=1000 0 0
Unmount /mnt/windows:
umount /mnt/windows
EXIT CODES
To facilitate the use of the ntfs-3g driver in scripts, an exit code is
returned to give an indication of the mountability status of a volume.
Value 0 means success, and all other ones mean an error. The unique
error codes are documented in the ntfs-3g.probe(8) manual page.
KNOWN ISSUES
Please see
http://www.tuxera.com/support/
for common questions and known issues. If you would find a new one in
the latest release of the software then please send an email describing
it in detail. You can contact the development team on the
ntfs-3g-devel@lists.sf.net address.
AUTHORS
ntfs-3g was based on and a major improvement to ntfsmount and libntfs
which were written by Yura Pakhuchiy and the Linux-NTFS team. The
improvements were made, the ntfs-3g project was initiated and currently
led by long time Linux-NTFS team developer Szabolcs Szakacsits
(szaka@tuxera.com).
THANKS
Several people made heroic efforts, often over five or more years which
resulted the ntfs-3g driver. Most importantly they are Anton Alta‐
parmakov, Jean-Pierre André, Richard Russon, Szabolcs Szakacsits, Yura
Pakhuchiy, Yuval Fledel, and the author of the groundbreaking FUSE
filesystem development framework, Miklos Szeredi.
SEE ALSOntfs-3g.probe(8), ntfsprogs(8), attr(5), getfattr(1)ntfs-3g 2010.3.6 February 2010 NTFS-3G(8)
